4.14-stable review patch. If anyone has any objections, please let me know.
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From: Zhu Yanjun yanjun.zhu@oracle.com
[ Upstream commit 9fd4350ba8953804f05215999e11a6cfb7b41f2b ]
When skb is sent, it will pass the following functions in soft roce.
rxe_send [rdma_rxe] ip_local_out __ip_local_out ip_output ip_finish_output ip_finish_output2 dev_queue_xmit __dev_queue_xmit dev_hard_start_xmit
In the above functions, if error occurs in the above functions or iptables rules drop skb after ip_local_out, kfree_skb will be called. So it is not necessary to call kfree_skb in soft roce module again. Or else crash will occur.
The steps to reproduce:
server client --------- --------- |1.1.1.1|<----rxe-channel--->|1.1.1.2| --------- ---------
On server: rping -s -a 1.1.1.1 -v -C 10000 -S 512 On client: rping -c -a 1.1.1.1 -v -C 10000 -S 512
The kernel configs CONFIG_DEBUG_KMEMLEAK and CONFIG_DEBUG_OBJECTS are enabled on both server and client.
When rping runs, run the following command in server:
iptables -I OUTPUT -p udp --dport 4791 -j DROP
Without this patch, crash will occur.
CC: Srinivas Eeda srinivas.eeda@oracle.com CC: Junxiao Bi junxiao.bi@oracle.com Signed-off-by: Zhu Yanjun yanjun.zhu@oracle.com Reviewed-by: Yuval Shaia yuval.shaia@oracle.com Signed-off-by: Doug Ledford dledford@redhat.com Signed-off-by: Sasha Levin alexander.levin@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/infiniband/sw/rxe/rxe_req.c | 1 - drivers/infiniband/sw/rxe/rxe_resp.c | 6 +----- 2 files changed, 1 insertion(+), 6 deletions(-)
--- a/drivers/infiniband/sw/rxe/rxe_req.c +++ b/drivers/infiniband/sw/rxe/rxe_req.c @@ -728,7 +728,6 @@ next_wqe: rollback_state(wqe, qp, &rollback_wqe, rollback_psn);
if (ret == -EAGAIN) { - kfree_skb(skb); rxe_run_task(&qp->req.task, 1); goto exit; } --- a/drivers/infiniband/sw/rxe/rxe_resp.c +++ b/drivers/infiniband/sw/rxe/rxe_resp.c @@ -742,7 +742,6 @@ static enum resp_states read_reply(struc err = rxe_xmit_packet(rxe, qp, &ack_pkt, skb); if (err) { pr_err("Failed sending RDMA reply.\n"); - kfree_skb(skb); return RESPST_ERR_RNR; }
@@ -955,10 +954,8 @@ static int send_ack(struct rxe_qp *qp, s }
err = rxe_xmit_packet(rxe, qp, &ack_pkt, skb); - if (err) { + if (err) pr_err_ratelimited("Failed sending ack\n"); - kfree_skb(skb); - }
err1: return err; @@ -1151,7 +1148,6 @@ static enum resp_states duplicate_reques if (rc) { pr_err("Failed resending result. This flow is not handled - skb ignored\n"); rxe_drop_ref(qp); - kfree_skb(skb_copy); rc = RESPST_CLEANUP; goto out; }